(Bloomberg) — Suicide bombers killed scores of worshipers
at two mosques in Yemen’s capital Sana’a during Friday prayers
as fighting escalated in the south and the country slipped
closer to civil war.

At least 137 people died in the attacks on the Badr and al-Hashoosh mosques, while almost 350 were injured, the local al-Masirah television channel said. The mosques, like most of the
capital, are controlled by the Shiite Houthi rebels, based in
north Yemen, who have been battling forces loyal to President
Abdurabuh Mansur Hadi and al-Qaeda militants.

It wasn’t immediately clear who was responsible. While
Islamic State claimed the bombings, it has had little
involvement in Yemen. Al-Qaeda, which has frequently targeted
the Houthis, said on Twitter that it didn’t order the attacks
and avoids striking areas, like the Sana’a mosques, frequented
by both Sunni and Shiite Muslims.

The escalation of violence threatens to split a country
that only reunified in 1990 after decades of division, and draw
in neighbors such as Saudi Arabia, the world’s biggest oil
exporter. The erosion of government authority has already
allowed al-Qaeda to take root in Yemen and use it as a base for
operations against Arab and Western nations.

Proxy War

The Saudis and the other Sunni monarchies of the Persian
Gulf support Hadi and see the Houthis as tools of Iran, the
Middle East’s leading Shiite power. The Houthis accuse the Gulf
Arabs of meddling in Yemen’s affairs, and say Hadi’s government,
counted by the U.S. as an ally against al-Qaeda, was secretly
backing the jihadist group.

The mosque bombings come a day after clashes broke out in
south Yemen, where Hadi and allies have regrouped after fleeing
the capital. Hadi was evacuated from his palace in Aden during
intense gun battles between his fighters and rival troops loyal
to Yemen’s former President Ali Abdullah Saleh, and the complex
was also hit by airstrikes.

Fighting escalated in other southern provinces on Friday.
Al-Qaeda-linked militants seized control of army camps in the
city of al-Hawtah, and executed 29 soldiers, according to the
Defense Ministry.

In Taiz, hundreds of troops loyal to the Houthis entered
the city without meeting armed resistance, though their arrival
did spark protests. Residents surrounded the Houthi encampments,
demanding that they leave, Abdulsatar al-Shameri, one of the
organizers, said by phone.

‘Ties That Bind’

Jets piloted by elements of Yemen’s military that support
the Houthis flew over Aden for a second day, and were fired at
by Hadi’s anti-aircraft artillery. At least 15 people were
killed in Thursday’s fighting in the southern port.

Hadi said the attack in Sana’a and the fighting in Aden
showed that the Houthis and the Sunni extremists of al-Qaeda are
“two sides of the same coin,” using violence in an attempt to
drag the country into a sectarian conflict, according to an e-mailed statement from his office.

The clashes in Aden highlight the alliance between Saleh,
who ceded power to Hadi in 2011 under a Gulf plan to end a year
of unrest, and the Houthis, according to Jordan Perry, a Middle
East analyst at U.K.-based risk assessment firm Verisk
Maplecroft.

The conflict threatens to “loosen the ties that bind
together the unified Yemeni state, fueling a revived southern
separatist movement,” Perry wrote in an e-mailed report
yesterday.

Saudi Arabia condemned both Friday’s suicide bombings and
Thursday’s attack on Hadi’s palace, and reiterated its backing
for the president as Yemen’s legitimate ruler, the official
Saudi Press Agency reported.

The U.S. State Department also condemned both attacks,
blamed the Houthis and Saleh for “violent incitement,” and
urged a return to peace talks brokered by the UN.